Improved design of lasers on optoelectronic chips will advance optical communications

Mar 26, 2014
Improved design of lasers on optoelectronic chips will advance optical communications
Current computer technology uses electronics, but a new laser design based on a thin-layered silicon chip may help increase data processing capabilities. Credit: Olga Miltsova/Hemera/Thinkstock

When it comes to data transmission, light is superior to electronics. An ability to transmit data in parallel by utilizing multiple light wavelengths allows optical fibers to carry more information than electrical cables. Computers are currently based on electronics, but they would benefit from employing optical signals. However, for this to become a reality, it needs to be implemented on a small scale and result in low power consumption.

Now, Vivek Krishnamurthy from the A*STAR Data Storage Institute in Singapore and his colleagues have designed a laser on a microelectronic chip that has a lower and a higher efficiency.

"By developing lasers on silicon, we can combine the electronic data processing capability of the microelectronic chip with the high energy efficiency of over distances ranging from a few micrometers within a chip to hundreds of meters in data centers," says Krishnamurthy.

The processing speed of the microelectronic chip is limited by its power consumption; most of the power is consumed by the connecting electrical wires and links. Optical links, on the other hand, consume practically no energy but are limited by the power consumption of the source, which is often a laser. For optical links to be feasible on a small scale, the electrical power consumption of lasers must be reduced, yet still be able to generate sufficient optical energy for transmission.

Lasers cannot be made from silicon as it is a poor light emitter. Instead, lasers are fabricated by bonding an active material based on indium phosphide—a good light emitter—to a thin silicon film. However, because silicon is better for carrying , the light from the laser needs to be routed through the via optical channels. This requires fabricating optical channels in silicon outside the laser region.

Generating light efficiently in the active medium and efficiently routing it via the silicon layer simultaneously reduces the electrical current required and increases the power generated. Calculations show that this silicon-based design will have a three to four times higher light generation efficiency than competing schemes.

This high efficiency makes the silicon-based laser design promising for making optical chips, which, says Krishnamurthy, is the next step for the project team. "We have begun the experimental demonstration of the laser," he says. "Our plan is to integrate this laser onto our silicon platform and develop a fully functional photonic system for applications, for example, in data communications and storage."

Explore further: Photonics: Enabling next-generation wireless networks

More information: Krishnamurthy, V., Wang, Q., Pu, J., Loh, T.-H. & Ho, S. T. "Optical design of distributed feedback lasers-on-thin-film-silicon." IEEE Photonics Technology Letters 25, 944–947 (2013). dx.doi.org/10.1109/LPT.2013.2257719

add to favorites email to friend print save as pdf

Related Stories

Photonics: Enabling next-generation wireless networks

Mar 12, 2014

Wireless transmission at microwave frequencies is important for high-data-rate transmission applications, such as mobile phone networks, satellite links and remote imaging. Now, Xianshu Luo and colleagues ...

Recommended for you

Finding faster-than-light particles by weighing them

1 hour ago

In a new paper accepted by the journal Astroparticle Physics, Robert Ehrlich, a recently retired physicist from George Mason University, claims that the neutrino is very likely a tachyon or faster-than-light par ...

Controlling core switching in Pac-man disks

Dec 24, 2014

Magnetic vortices in thin films can encode information in the perpendicular magnetization pointing up or down relative to the vortex core. These binary states could be useful for non-volatile data storage ...

World's most complex crystal simulated

Dec 24, 2014

The most complicated crystal structure ever produced in a computer simulation has been achieved by researchers at the University of Michigan. They say the findings help demonstrate how complexity can emerge ...

Atoms queue up for quantum computer networks

Dec 24, 2014

In order to develop future quantum computer networks, it is necessary to hold a known number of atoms and read them without them disappearing. To do this, researchers from the Niels Bohr Institute have developed ...

New video supports radiation dosimetry audits

Dec 23, 2014

The National Physical Laboratory (NPL), working with the National Radiotherapy Trials Quality Assurance Group, has produced a video guide to support physicists participating in radiation dosimetry audits.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.